1 files changed, 69 insertions, 4 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2e132b9e7a93..09bf2c5f8b4b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -789,6 +789,57 @@ static inline int page_is_buddy(struct page *page, struct page *buddy,
         return 0;
 }
 
+#ifdef CONFIG_COMPACTION
+static inline struct capture_control *task_capc(struct zone *zone)
+{
+        struct capture_control *capc = current->capture_control;
+
+        return capc &&
+                !(current->flags & PF_KTHREAD) &&
+                !capc->page &&
+                capc->cc->zone == zone &&
+                capc->cc->direct_compaction ? capc : NULL;
+}
+
+static inline bool
+compaction_capture(struct capture_control *capc, struct page *page,
+                   int order, int migratetype)
+{
+        if (!capc || order != capc->cc->order)
+                return false;
+
+        /* Do not accidentally pollute CMA or isolated regions*/
+        if (is_migrate_cma(migratetype) ||
+            is_migrate_isolate(migratetype))
+                return false;
+
+        /*
+         * Do not let lower order allocations polluate a movable pageblock.
+         * This might let an unmovable request use a reclaimable pageblock
+         * and vice-versa but no more than normal fallback logic which can
+         * have trouble finding a high-order free page.
+         */
+        if (order < pageblock_order && migratetype == MIGRATE_MOVABLE)
+                return false;
+
+        capc->page = page;
+        return true;
+}
+
+#else
+static inline struct capture_control *task_capc(struct zone *zone)
+{
+        return NULL;
+}
+
+static inline bool
+compaction_capture(struct capture_control *capc, struct page *page,
+                   int order, int migratetype)
+{
+        return false;
+}
+#endif /* CONFIG_COMPACTION */
+
 /*
  * Freeing function for a buddy system allocator.
  *
@@ -822,6 +873,7 @@ static inline void __free_one_page(struct page *page,
         unsigned long uninitialized_var(buddy_pfn);
         struct page *buddy;
         unsigned int max_order;
+        struct capture_control *capc = task_capc(zone);
 
         max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
 
@@ -837,6 +889,11 @@ static inline void __free_one_page(struct page *page,
 
 continue_merging:
         while (order < max_order - 1) {
+                if (compaction_capture(capc, page, order, migratetype)) {
+                        __mod_zone_freepage_state(zone, -(1 << order),
+                                                                migratetype);
+                        return;
+                }
                 buddy_pfn = __find_buddy_pfn(pfn, order);
                 buddy = page + (buddy_pfn - pfn);
 
@@ -3710,7 +3767,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
                 unsigned int alloc_flags, const struct alloc_context *ac,
                 enum compact_priority prio, enum compact_result *compact_result)
 {
-        struct page *page;
+        struct page *page = NULL;
         unsigned long pflags;
         unsigned int noreclaim_flag;
 
@@ -3721,13 +3778,15 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
         noreclaim_flag = memalloc_noreclaim_save();
 
         *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
-                                                                        prio);
+                                                                prio, &page);
 
         memalloc_noreclaim_restore(noreclaim_flag);
         psi_memstall_leave(&pflags);
 
-        if (*compact_result <= COMPACT_INACTIVE)
+        if (*compact_result <= COMPACT_INACTIVE) {
+                WARN_ON_ONCE(page);
                 return NULL;
+        }
 
         /*
          * At least in one zone compaction wasn't deferred or skipped, so let's
@@ -3735,7 +3794,13 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
          */
         count_vm_event(COMPACTSTALL);
 
-        page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
+        /* Prep a captured page if available */
+        if (page)
+                prep_new_page(page, order, gfp_mask, alloc_flags);
+
+        /* Try get a page from the freelist if available */
+        if (!page)
+                page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
 
         if (page) {
                 struct zone *zone = page_zone(page);